.footer {
  height: 1.46666667rem;
  display: flex;
  align-items: center;
  color: rgba(255, 255, 255, 0.5);
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  width: 100%;
  background: -webkit-gradient(linear, left top, right top, from(#7089ff), to(#8959dc));
  background: linear-gradient(to right, #7089ff, #8959dc);
  /* 标准的语法 */
}
.footer a {
  display: block;
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
}
.footer a span {
  display: inline-block;
  width: 0.6rem;
  height: 0.48rem;
  margin-bottom: 0.13333333rem;
}
.footer a:nth-child(1) span {
  background: url(../images/img1.png) no-repeat center;
  background-size: contain;
}
.footer a:nth-child(2) span {
  background: url(../images/img2.png) no-repeat center;
  background-size: contain;
}
.footer a:nth-child(3) span {
  background: url(../images/img3.png) no-repeat center;
  background-size: contain;
}
.footer a:nth-child(4) span {
  background: url(../images/img4.png) no-repeat center;
  background-size: contain;
}
.footer a:nth-child(5) span {
  background: url(../images/img5.png) no-repeat center;
  background-size: contain;
}
.footer a.active:nth-child(1) span {
  background: url(../images/img_a1.png) no-repeat center;
  background-size: contain;
}
.footer a.active:nth-child(2) span {
  background: url(../images/img_a2.png) no-repeat center;
  background-size: contain;
}
.footer a.active:nth-child(3) span {
  background: url(../images/img_a3.png) no-repeat center;
  background-size: contain;
}
.footer a.active:nth-child(4) span {
  background: url(../images/img_a4.png) no-repeat center;
  background-size: contain;
}
.footer a.active:nth-child(5) span {
  background: url(../images/img_a5.png) no-repeat center;
  background-size: contain;
}
